Follow below steps to boot the Androidthings on Raspberry Pi3
Download the prebuilt image from https://developer.android.com/things/preview/download.html
$ wget -c https://dl.google.com/dl/androidthings/rpi3/devpreview/1/androidthings_rpi3_devpreview_1.zip
$ unzip androidthings_rpi3_devpreview_1.zip
this will unzip and create iot_rpi3.img image which we need to install on SD card.
$ sudo dd bs=1M if=./iot_rpi3.img of=/dev/sdb
where /dev/sdb is assumed to be device name of SD card which we needs to connect to Raspberry Pi.
This will flash the image on SD card, and create 5 partitions like below as seen using mount command on desktop,
$ mount
/dev/sdb11 on /media/myuser/oem type ext4 (rw,nosuid,nodev,uhelper=udisks2)
/dev/sdb6 on /media/myuser/_ type ext4 (rw,nosuid,nodev,uhelper=udisks2)
/dev/sdb1 on /media/myuser/RPIBOOT type vfat (rw,nosuid,nodev,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec,flush,uhelper=udisks2)
/dev/sdb13 on /media/myuser/gapps type ext4 (rw,nosuid,nodev,uhelper=udisks2)
/dev/sdb15 on /media/myuser/data type ext4 (rw,nosuid,nodev,uhelper=udisks2)
Now, Put the SD card to RPi and connect the ethernet cable to RPi. Once power is connected, Androidthings will boot and stop at the launcher which displays “Androidthings” logo / text and at footer will show the Ethernet IP address, in our case it was 192.168.1.101
Now, on desktop install adb as,
$ sudo apt-get install android-tools-adb
Connect Adb to Androidthings RPi,
$ adb connect
This will connect the adb, now use adb shell to login to shell
$ adb shell
To connect to Wifi, follow steps from https://developer.android.com/things/hardware/raspberrypi.html#connecting_wi-fi
More reference : https://developer.android.com/things/sdk/index.html